On The Nose
by whatifellinlovewith
Summary: "She ignores the churn of nausea in her stomach at the scent of her familiar morning brew, swallows it back as she reaches for the cup. Intent on not letting him know of the uncertainty swirling in her head, the queasiness twisting in her gut." A season 2 AU. For Lou.


_**On The Nose**_

* * *

 **Set post-Overkill. For Lou.**

* * *

His steps are quiet when he enters the break room, only her acute awareness of the door clicking closed behind him drawing her gaze from its lock on the sink drain up to him. A smile graces his lips, kind and sweet as he steps towards her, holding two oh-so-familiar paper mugs in his hands, one outstretched towards her.

She ignores the churn of nausea in her stomach at the scent of her familiar morning brew, swallows it back as she reaches for the cup. Intent on not letting him know of the uncertainty swirling in her head, the queasiness twisting in her gut.

The sip she forces herself to take is small, hopefully not enough to have her stomach rebelling against her, just for the sake of not tipping him off to her discomfort.

He knows her too well, has too much power to turn her heart upside down as much as he did her world, to read the looks on her face as much as the cues of her body. And her fears are only confirmed by the furrow of his brow as he watches her, the trace of his gaze over the length of her body.

"You okay?" he asks.

She nods, no matter the nerves the question evokes in her stomach. "Just waiting for the boys to get back with our witness," she answers.

"You sure?" he says this time. He sets his coffee next to hers on the break room counter, stepping towards her. "Because if you're not, I could try to make you feel _better_."

And he's lifting his hand, holding his palm up in the space between them far too pointedly, eyes flicking over the length of her body again. The whole moment laced with too much implication, innuendo, and she can't…can't let him get any closer. Not when– Not with— Not—

" _Castle_ ," she hisses, taking a stumbling step back because he's too close and it's too much and she _can't_.

Not today.

But his face falls, and he steps away from her, too, eyes falling. He reaches for his coffee cup again, takes a sip as though to seem nonchalant despite the tension in his shoulders, the draw of hurt at the corners of his lips.

"Right. Sorry," he mumbles. "That was…out of line." He pauses, takes another sip off his coffee. "So, uh, how was your weekend? How's Demming?"

 _What?_

Her head jerks up, hand curling tight at the edge of the counter as she catches his gaze. The seemingly benign curiosity behind it, met only with a hint of the jealousy that's simmered since the first case they worked with Demming.

He thinks this has to do with _Demming_?

"Castle—"

His gaze cuts to hers, and words of reassurance that her distancing herself from him has nothing to do with Demming are already on the tip of her tongue.

But the door swings open at that very moment, revealing Esposito and Ryan, the latter lingering behind his partner, sniffing at his shirt collar.

"Your witness is here, Beckett," says Espo. "And fair warning, she's a weird one."

* * *

He follows her into the interrogation room where their witness, Mia, is sitting as though his heart doesn't feel like it's been beaten by her withdrawal. By her sudden interest in a dashing robbery detective and loss of interest in him. As though everything is still perfectly fine and happy and fun.

As though he doesn't go home to an apartment bare of her and miss the friendship they shared while she lived with him, the moments stolen together, shielded by the darkness of night.

His cup of coffee stays clutched in his hand as he steps into the conference room where Mia sits, waiting for them. As he slides into the seat next to the one Beckett takes, offering a smile at the witness in a feeble attempt to diminish her obvious discomfort.

She just shoots him a glare, crinkling her nose in disgust before turning back to Beckett.

"Let's just get this over with," she says.

Beckett's gaze flicks upwards, eyes wide in shock at the words she obviously didn't expect, those so rarely spoken in simple conversations such as this one. She offers a half-hearted smile to mask her confusion, shifting in her seat so she can cross her arms over the table, lean forward in that information-demanding way she's mastered.

"Uh…okay." she says. "So, what do you remember about the murder this morning?"

Mia launches into her explanation, a quick, clipped retelling of events. How she heard two gunshots, was joined on the elevator by a man in a ski mask who didn't kill her, but got off on the ground floor, and she called 911. Speaking the words simply, emotionlessly, rushing through them as much as her question when she finishes. "Can I go home now?"

Beckett's eyes widen even more at that, and if he wasn't so fascinated by the strange woman before them, he would be muffling a laugh behind his palms at her confusion as to how to handle this.

"Uh, no," she answers.

"Why not?" asks Mia.

He bites his lip to tamper a grin, turning back to Beckett to see her obvious resistance of an eye roll, the way her teeth catch the corner of her lip as she stares at Mia. Baffled, no matter her experience. Confused by this woman that the boys deemed strange, who didn't fail to disappoint.

Oh, if she's more involved than merely being their 911 caller, this could turn out to be a very interesting case.

"Because I'm not done asking you questions just…yet," responds Beckett, matter of fact as though it's the most obvious thing in the world.

He supposes it is, though, to most people.

But not to Mia, it seems. She cringes in response, pushing herself away from the table as she speaks. "Can we make this quick, then? Your hormones are killing me."

His gaze shifts to Beckett to catch her reaction before Mia's words settle in his mind. Before he finds his jaw falling open, finds himself watching Beckett's do the same, fingers curled so tight around her pen that her knuckles are blanching. Eyes so wide now it would be laughable if he wasn't so scared of her response.

But she manages to keep it civil, her words stuttered as they tumble from her lips, laced with confusion, with incredulity. "My _what_?"

Mia motions to Beckett with a jerk of her head, face still screwed in disgust when she clarifies in a way that offers _no_ clarity.

That has his pulse spiking, breaths jerking to a stop in his chest as his jaw hangs open again.

"Your pregnancy hormones. They _reek._ "

Beckett's pen clatters to the table, mouth slamming shut at the words, cheeks blooming bright red as she _stares_ , wordless, at the woman sitting across from her.

The woman who just suggested— No, not suggested. Who just said—

Beckett is _pregnant_? If this woman is to be believed, that is. His gaze drifts along her frame, lingers on her stomach for a moment too long only to flick away when she scowls at him.

But she could be— She might be pregnant? She's _pregnant_?

And he could be…but so could Demming…and he's not even sure Mia is to be believed, needs to know at least that before he allows his mind to go racing.

"Her _what_?" He's the one searching for clarification now, gaze flicking between Mia and Beckett, searching for humor in the witness' eyes, for murderous intent in Kate's.

Or honesty. Realization. Embarrassment or guilt. Anything but the blank stare she offers now, the traces of absolute shock flashing as she glares at Mia, as her hands curl into fists and her teeth drag across her lower lip.

Mia laughs in response. "I take it you guys didn't know detective baby mama was knocked up?" she says.

Kate's fist clenches tighter, and he watches the twitch of her arm, tries to figure out if she's trying to keep herself from hitting Mia. Or shoving herself away from the interrogation room table and running from this entire conversation.

But he finds fascination settling in his gut now, a familiar curiosity brewing among the sparks of surprise that light within his chest. He leans forward in his seat, towards Mia.

"How do _you_ know?" he asks.

She narrows her eyes at him, levels him a glare that is far too similar to his partners. "I just told you. It _reeks_ ," she says, pauses as though expecting that to explain everything only to punctuate her next words with an exasperated sigh. "I can smell it."

" _Smell_ it?" he asks. "Can you smell anything else?"

Mia glances back at Kate. "She's been having some morning sickness, because even though she brushed her teeth and had coffee, I can smell the sulfur on her breath," she says.

He turns to Kate for confirmation, gets it in the way her face blanches.

And it sends his world spiralling. This potential child of his. Of his and Kate's. This baby that may or may not exist, that may be his and hers, that may turn their lives upside down or maybe upside right, help fix this mess they've gotten themselves into or tear them apart after they've finally started to move forward together.

It's dizzying. Blurring the world around him to nothing but the ashen of Kate's face now, the possibilities that have his heart stuttering with…hope?

"And she didn't know," continues Mia, "based on how surprised she is now. But I think she suspected, because now she reeks of nerves and pregnancy. She's not very far along, though."

His gaze flicks down to her stomach once more, notes the lack of swell there, the lack of evidence of life but if she's not far along their wouldn't be.

And she was sick, apparently— _shit_ , that explains her mood this morning, how not okay she appeared to be.

And she supposedly reeks of pregnancy hormones to Mia.

And if she is pregnant, he could—

"And you might be the father," adds Mia.

He turns back to her, gaze snapping wide in their witness' direction even as he feels Beckett's land on him, at last. "You can smell _that_?"

"No," she answers, the single syllable flat, emotionless. "But I can smell how hopeful you are. I'm not an expert on interpersonal relationships, but it doesn't seem like the reaction of a mere coworker."

It isn't. _Oh_ , it so isn't. The race of his heart and spinning in his head and quickening of his breath, the flash of memories through his mind of nights spent with her in his bed, laughs fading to moans under the touch of his hands, the rush of lust through his body that may have led to _this._

 _Oh god._

They might be having a _baby_.

The door clicks open link a punctuation to the thought, revealing Ryan and Esposito as they step into the room, motion between himself and Beckett with shocked gazes, an explanation coming in uncertain words.

"It seems like, uh, you two have…things to talk about."

He nods his response, turning to look at Beckett only to catch her pushing herself from her chair, rushing from the room with a mumbled _thank you_ as Mia just sits there, indifferent, watching.

His hands flatten against the table when he pushes himself from his seat, knees quaking beneath his weight as he rushes after Kate, just a few feet behind her.

She swipes her bag from her desk and rushes towards the bathroom, a hand pressed to her mouth, and despite his better judgement, the struggle of the past few weeks and all the new information that makes no sense beyond instinct. Intrinsic knowledge of what he has to do.

For himself. Hopefully for her.

So he follows.

* * *

The door swings open loudly just as she drops to her knees on the precinct's tiled bathroom floor, closes with a thud that mirrors that of the footsteps echoing in her ears. Just before she gives up on paying attention, curls her hands around the toilet seat and heaves forward with the final lurch of her stomach.

Castle's behind her in a second, leaning over her and grabbing for her hair, sweeping it away from her face with delicate, distracting brushes of his fingers against her jaw, her neck. His free hand flattens against her back, rubbing circles there until her stomach calms and she can sink back against the wall of his chest.

When did he drop to the floor with her?

His fingers release her hair to massage her shoulder instead, offer comfort as though he didn't just find out from a witness in a murder case with an apparently incredible sense of smell that she might be having his baby.

"Morning sickness, or emotional reaction?" he asks, a whisper too close to her ear.

She pushes away from him, slowly lifting herself onto shaky legs, reaching over the flush the toilet as her other hand closes around the strap of her purse. He stands with her, leaning against the stall wall for a moment before he's stepping out, towards the vanities and sinks that line the bathroom wall.

It's only after she brushes her teeth, thanking her past self for stuffing a toothbrush and toothpaste into her bag the other day when the nausea first started haunting her, that she turns back to him. Allows him to see the sure vulnerability in her eyes, the nervous twitch of her lips into a small smile when she offers her response.

"I don't know," she admits. "I haven't…taken the test yet?"

His eyes widen, gaze locked on hers as he shoves his hands into his pockets. " _The_ test?" he asks. " _Yet_?"

She swallows the responding rise of bile in her throat, nods her head as she does so. Stuck silent, chest achingly still, heart a fluttering hopeful, fearful mess, breaths uneven and shaky. Her hand pats the vanity at her side, feeling for her purse until she can draw it towards her, fish her hand inside so her fingers can close around the plastic wrapper of the pregnancy test she couldn't bring herself to take this morning.

Her hands had been shaking, this same plastic wrapper crinkling in her grasp as she'd stared in the mirror at a panicked reflection of herself.

Why isn't she as panicked now?

"Oh," he breathes.

It has her blinking from her thoughts, eyes snapping back to his, forbidden realization dawning within her. Because he's staring at her with bright eyes, shining with hope and lingering apprehension and _this_ is why she's not panicked into stillness, scared of facing the potential of their new reality.

But he looks scared now, staring at the white wrapper with such hope it's shocking, staring at her with so many unspoken questions and she scrambles to answer the first one she can.

"If I am, it's yours," she promises. "Definitely yours. You were the only one." Her hands clutch tighter at the pregnancy test as she looks up at him, his earlier question flashing into her mind, drawing more clumsy words from her chest. "Demming wasn't anything. Just…ill advised flirting, but it was only you."

Only him when it shouldn't even have been him. When it was nothing but the celebration of taking down a serial killer that had them stumbling into bed the first time, all busy hands and clumsy kisses, both shirtless before she'd fallen onto the mattress, drawing him on top of her.

She'd been stupid to expect it to not lead to something more. To drinks on his couch leading to a heated makeout session and seeing him coming out of the shower with mussed hair having her all but jumping him in the kitchen. That it wouldn't have feelings budding no matter how hard she'd tried to tamper it. That it wouldn't have arousal bubbling within her like never before, ruining her inhibition and logical thinking and restraint until…

Until now. When she might be—probably is—pregnant with his baby.

Yeah, it might not have have been the smartest thing to do, jumping into bed with him all the while failing to define it, leading up to _this_ even though a baby had never entered her mind as a possibility until just a few days ago.

"Okay," he breathes in response, in an awe-filled tone that gives her far too much credit for nothing. "That's…good."

She blinks the haze from her vision, catching the sincerity that gleams in her eyes with her own. "Yeah?"

His smile widens, blooms across his face, so happy and hopeful and _beautiful._ "Yeah," he confirms. He glances down at the pregnancy test still clutched in her hands. "You should take it," he says.

Her gaze falls as well, her nod slow, slight. "Yeah, I should."

And she does, no matter her quivering hands and the nerves that twist knots in her gut, the painful, broken beats of her heart or the burn in her chest when she holds her breath.

She lingers in the stall when she's done, waiting for the result to appear with baited breath, staring at the fade in of her fate. The possibility of this new, life-changing thing, life-changing _life_ within her staring back at her in the window of a pregnancy test until—

Her knees are shaky when she steps from the stall, finds him leaning against the sinks. So is her hand when she reaches out, sets the pregnancy test next to him so he can see the result.

His breath catches, her heart stilling in anticipation.

And then he's turning towards her, smiling as he reaches for her. One hand flattens at her side, the other pressed to the dip of her spine as he pulls her close, wraps her in his arms and clings to her like she just granted every wish she didn't know he had.

"We need to talk," she whispers against his shoulder.

He nods. "We do," he mumbles. "But later. For now, just…"

The sentence trails to silence, but she doesn't need him to continue it. The wrap of his arms around her is enough.

* * *

They walk out of the bathroom together to find Ryan and Esposito staring at them, not even bothering to hide their curiosity. But Beckett is back to herself, a smile on her face and a strength to her step just like the detective they all know.

It doesn't keep Esposito from raising his brown in silent question, Ryan from letting his gaze fall unabashedly to her stomach as though searching for evidence of what they found.

She doesn't seem to care. "Did you get anything from Mia?"

Esposito sighs, exasperated, even as he nods his head. "A description of the potential gunman," he answers, pauses. With one hand, he motions to them both, lips quirking in teasing. "How 'bout you guys?"

Kate doesn't answer. But everyone knows from the pink stain to her cheeks, dip of her gaze and quiet mumble she offers as she swipes Esposito's interrogation notes from his desk.

* * *

He escorts her into the loft that night, when their case is at a stands till and conversations have been put off for too long, bubbling joy and uncertainty leading them to his home the moment Montgomery sends them away with a knowing smile on his face. But she finds she doesn't mind the dismissal, needs the conversation yet to be had as badly as Castle seems to, needs the reassurance after a day of letting the new, the reality, sink into her heart and remind her of the mess they've made.

That they're having a _baby_ , and they were never even more than friends.

Well, more than friends who spent all day pretending that was all they were only to fall into each other at night, a clash of lips and searching hands. Celebratory drinks at the end of a case that had her losing her inhibition and pressing her lips hard to his. A movie that began with a couch-worth of space between them that ended with her thighs framing his lap and shirt lost somewhere in his living room. An announcement that she was moving out ending with him staining her neck with his kisses as he pressed her against the bookshelves in his office.

Without ever talking about it, setting labels or even suggesting that they were anything more than friends.

She almost wishes she could say they were careful, that the bloom of new life in her abdomen was the product of that minute possibility no matter how careful you are. But as she steps into his apartment, she's reminded that they really weren't, were far too rushed, too dependent on the pill she had been failing at taking regularly.

And now—

"Stop thinking so loud," he whispers. His hand flattens against the base of her spine, drifts upwards so his fingers can curl at the collar of her jacket and draw it from her shoulders.. "Or, if you're going to think so much, at least tell me what you're thinking so I can try to reassure you."

Her gaze cuts to his over her shoulder, teeth catching at the corner of her lip. "You really think words are going to make everything okay?"

He doesn't respond, not right away. Just sheds his jacket and lets his hand return to where it had been resting at the base of her spine as though it's _normal._ For him to be standing so close, touching her in such a simple way, so very comfortable with the contact.

Too calm for the new situation they're facing, this new facet to their lives that can't be ignored.

How is it that the nine-year-old on a sugar rush handles true stress so much better than she does?

"I think that not speaking gets people into messes, and I don't want that to happen to us." He answers her previous question, his hand pressing hardest against her back as he leads her towards the couch. The pressure of his palm has her turning to face him, to catch the way his gaze flicks to the flat of her stomach. "Especially not now."

Butterflies erupt beneath his gaze, a dizzying flurry of movement within her that has her dropping onto his couch, resting her head against the cushions behind her. She flattens her palm against her belly, the action so foreign, so strange that she almost pulls it away.

But the knowledge that life grows within her is almost reassuring, not nearly as scary as she thought it would be when Castle's at her side, offering calm comfort like she never would have expected.

"What do you want to happen to us?" she whispers. "Now that we're…"

Now that they're _what_? Friends. More than friends. Lovers? And _parents._

"Now," she finishes lamely.

He shrugs, shifting closer to her. "That depends on you."

Her heart drops, or stutters, or lifts. Flip in her chest, nauseating and relieving and making her curl her hands into fists, swallow against the instinct to run. "Me?"

His nod is slow, sure, met with his hand reaching over, curling tight at her knee. He catches her gaze, eyes shining bright with such intensity, such hope that it has her heart stilling in her chest, cheeks warming under his gaze.

Memories of nights spent together flash behind her eyes, laced with knowledge of how skilled he is at drawing such reactions from her. Of nights spent hiding her blush with the press of her cheek to his chest, pretending he didn't make her heart flutter with the dust of his fingertips across her skin, losing herself to a moment of freedom, of sensation, without considering the repercussions.

 _These_ repercussions.

"Yeah," he breathes in response. "How we go about this…it's all up to you."

She responds with a bob of her head, a smile that curls, hesitant, at the corners of her lips. Her hand coasts along her leg, finds it where it remains on her knee, fingers threading into the gaps between his. She squeezes his hand gently, eyes drifting back up to his.

"What are the options?" she asks, hearing the waver in her own voice that's met with the tight clench of dread in her chest, the flood of anxiety through her system. A voice somewhere, distant and quiet and in the back of her mind reminds her that she doesn't even know what she wants him to say, what she _doesn't_ want him to say.

Her whole world, it seems, is suddenly teetering on the edge of what she'd thought she'd wanted and _this_ strange phenomenon of her pulse spiking at his proximity, fears easing at his touch. Of being pregnant with his baby and _not_ wanting to flee. hide from his seeming ease with all of this, the spark in his eyes that tells her he might have wanted this, with her, at some point in the future anyway.

It should terrify her, send a torrent of horror to pound through her body, this newfound information, the sudden realization of the possible depth of his feelings.

But she finds herself shifting closer to him, squeezing his hand in silent reassurance even as words fall from her lips to fill the silence, spur his own. "You already got me pregnant, Castle. I doubt anything you have to say could freak me out more than that."

A puff of laughter breaks free from his chest, lifts some of the severity from his gaze when he looks back up at her. "Well, when you put it _that_ way," he says, only to close the space between them, press his thigh to hers, lean forward enough to spark a hint of longing within her when her eyes flick to his lips. "There's just…different ways we could go about this."

"Which are?"

He shrugs, but she feels him go tense against her, can sense the nervous energy around him that must now be mirrored by her own. A betrayal of his calm exterior as he clutches at her as though trying to ensure she won't run away in response to whatever he has to say.

"We could go back to being just friends," he says. "Balance parenting together." His pause lingers for a long time, until his gaze is flicking up to hers, eyes wide. "If you even want me in the baby's life, that is."

Oh. _Oh_.

Her free hand comes up, curls around the very spot it usually occupies before she pushes herself onto her toes and presses her mouth to his. Fingers thread through the curls at his name, thumb tracing the knot of muscle near the sharp angle of his jaw as she tilts towards him, presses herself harder against his side.

How could he even think, after all they've been through—after today—that she'd keep his child from him? That she'd even survive doing this without him?

"Of course I want you in the baby's life," she mumbles, words foreign on her tongue, too honest to hold back.

Almost as scary in their sincerity as the surge of regret that wells within her, of desire for his alternate scenario, their other possible future includes more than mere friendship. Doesn't involve going back to forbidden lust and silent affection, to subtext they pretended not to understand, distance between them. The loss of what physical intimacy they've developed since they first fell into bed together.

"Or?" she prompts, the word a whisper that has his eyes flicking back to hers.

The space between them narrows as he leans closer, but she doesn't try to pull away.

"Or," he begins, "we could try to be more." His hand slips from beneath hers, away from her leg to curl at her side, thumb skimming low on her stomach as his fingers drift along her waist, splay at the curtain of her ribs. "We could be together, learn how to be with each other as we get ready to be…parents."

Her heart jumps, her response already curling at the tip of her tongue before her brain can rationalize.

It's probably unwise, being together now, allowing a relationship to bud between them when the possible consequences of it falling apart are so grand. When their ability to be a family may depend on their relationship's success. When their foundation for more is this friendship, a handful of nights together and a baby they didn't plan on.

But she presses her lips to his, knowing it's answer enough the moment his arms wind around her body and haul her onto his lap.

* * *

They solve the case within days, with Mia's help and the friendship Castle managed to form with her. Kate's shoving their killer into a holding cell after a short investigation, Ryan and Esposito still discussing Mia's hypersensitive sense of smell and he finds himself accompanying Mia to the precinct elevator.

"Thank you for all the help," he tells her, slapping the elevator button.

Her gaze cuts to him, eyes narrowed. "With your investigation? Or making you realize you knocked up your girlfriend?"

Laughter bubbles within him, only for him to swallow it back, let his gaze drift to where Beckett is watching, leaning against the wall nearby. "Uh, both," he answers. "Beckett and I are…grateful for the way we found out and the fact that it forced us to talk it through, get through it together."

Mia's responding eyeroll is almost predictable, almost has his laughing again.

"She would thank you herself, but she didn't want to assault you with the, uh, reeking scent of her pregnancy hormones," he explains.

"Good," says Mia. "It's even worse now that her pheromones are extra strong because she's all lovey with you."

The responding smile blooms across his face, his gaze returning to catch the upturn of Kate's lips.

And the reaction must cause _some_ kind of scent, because it has Mia gagging. "Ew, now yours are too."

His step back is stumbling, his smile lingering and true. "Sorry," he offers.

But Mia motions to the elevator as they ding open. "Whatever. I'm leaving anyway," she says, stepping onto the lift. Her gaze drifts over his shoulder, towards Kate, when she turns back to face the open doors, and he watches her nose crinkle in disgust despite the words that fall from her lips. "As much as a screaming, smelly little person that _reeks_ of diaper is the last thing I would want, you guys seem happy," she says. "Congratulations."

Before he can muster an adequate response, the doors are sliding closed and he's turning away, towards Kate as she walks towards him, and his hand splays at her waist despite the _no touching at the precinct_ rule she'd instated.

"What'd she say?" she asks.

He smiles, draws her closer, eyes falling to the flat plane of her stomach. "She offers her congratulations," he tells her.

Kate pulls back, eyes narrowed. "Really?" she asks. "That doesn't sound like Mia."

It draws a shrug from him, has him pulling her even closer so her body is pressed to his. "Well, she prefaced it by informing me that a screaming, smelly little person who reeks of diapers is the last thing she would want."

"Ah," she breathes in response. "That's more like it."

And she punctuates the sentence with a chuckle that dies on her lips when he leans down to kiss her.

* * *

 **Lou, her magnificent the prompt overlord and friend extraordinaire, I hope this fic is satisfactory for your birthday (even though it's not from one of your prompts). I cannot express my gratitude that we've gotten to know each other over this past year, for your acceptance and support. You are an amazing person and friend and don't ever let anyone (including yourself) tell you otherwise. (Oops I'm sappy). xoxo**

 **And to everyone else who read this, I don't know what this is, but I hope you enjoyed! As always, immense gratitude goes to Lindsey for looking this over for me.**


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